You might think you deserve a raise, but that doesn't always mean your boss agrees with you. And no, you can no longer heap all the blame on a bad economy. At 7.7%, the unemployment rate is the lowest it has been since December 2008. In February alone, the Labor Department reported that the economy added 236,000 jobs. So, what does this mean for you? It's the perfect time to ask for a bump in pay.

If it's been a while since you increased your salary and you're coming up against a wall, the most likely reason is...you. Here are the top ten reasons you haven't landed the increase you so desperately want, and how to fix them.

You Have Unrealistic Expectations

In 2012, a typical merit raise averaged 1.9 to 2%, while the highest-performing employees received closer to a 4% raise. To determine if you're worthy of that 4% (or more), it's vital to check in with your boss regularly so you're on the same page about your performance. Does your boss think you turn in above average work or is there an area she thinks you're struggling with?

Also, does your company give raises at a certain time each year (say, at annual review time), or are they rolling, based on performance? If it's the former, make sure to time your request for optimal results.

Finally, remember to consider your company's financial situation. Asking for a big raise when the company is struggling can come off as out of touch.

You Didn't Do Your Research

Before deciding how much of a raise you deserve, look up the standard industry salaries for similar positions on sites like Salary.com and Glassdoor.com. That will give you a point of reference for framing the conversation. But it's not enough to cite averages-you also have to make a case for your personal performance, and how you're going above and beyond your job duties. Which brings us to...

You Do Only What's Expected of You

Doing your job is what you are paid for, whereas a raise is a sign that your boss sees that you're contributing at a higher level than what you were originally hired to do. One good rule of thumb is to be an employee who makes your boss's job easier: Volunteer to take on additional projects and think about what you can do to lighten her workload. Or notice what she is complaining about, and figure out how to solve a problem within your department. If you present solutions for her now, you'll find your superior more willing to meet your demands later.

You Don't Call Attention to Your Accomplishments, or You Act Entitled

Neither of these extremes will help you get that salary bump. And, admittedly, mastering the fine art of self-promotion isn't easy. First, make sure that your boss is aware of everything you've taken on. And feel free to share your successes—they show that you're capable and competent. Just be subtle about it: Set up a meeting to discuss the projects you're working on, mention key wins you've had and ask for feedback on how you could still do better.

Another good strategy: Rely on third-party praise. Copy your boss on an email chain discussing a successfully-executed project or forward her a particularly moving compliment from a client.

You're Not Staying Current

Evaluate your skill set: How much has it changed since you started in your industry? In certain jobs, a lack of tech finesse, or the ability to stay on top of the latest trends, can trip you up—and cause your salary to stagnate. That's especially true for older workers, who, unfortunately, can face age discrimination in the office: In a survey of people 50 years old or older, over one-third of respondents reported that they or someone they know has faced age discrimination at work, and 25% of all complaints filed with the U.S. Equal Employment Opportunity Commission involve age discrimination.

But there's no reason to let a lack of skills hold you back. Bookmark and follow industry blogs, and look into workshops and courses teaching the latest industry developments. You can even mention them to your boss and see if the company will foot the bill for your continuing education. Bonus: He'll see that you're trying to sharpen your skills.

You're Unable to Problem Solve, or Love to Complain

Be honest with yourself: Is your gut instinct to tell your boss every time an issue arises, or do you try to navigate through hurdles yourself?

If it's an issue that truly needs to be escalated, by all means, manage up. But a broken printer is a good example of what not to kick up the food chain. Also, beware of becoming the employee who's always got a gripe, whether it's about company policy or your coworker you just can't stand. Ultimately, the people who get raises are the employees who consider it their jobs to provide solutions, not raise problems.

You Don't Pay Attention to the Details

Does your boss tell you to fix the same type of mistake over and over again? Do you constantly need reminders? Do you usually ask the same question twice? If you answered "yes" to any of these questions, a raise is (most likely) not in your near future.

Take notes while your supervisor is giving instructions, see if you can find the answer yourself before asking questions, and each time you make a mistake, write down for yourself what it was, why it happened and how you'll prevent it from happening in the future.

You Made it a Personal Matter

Your argument for why you deserve a raise should be focused on your work ethic, your accomplishments and your value to the company—and those three things alone. What should be left out of the proposal? Your student debt, your rent, your hospital bills or the fact that you "just can't make ends meet on this salary." Bottom line: A raise will be awarded based on your merit, not your sob story.

You Didn't Ask for One

If none of the above eight reasons apply to you, then seriously, ask for a raise. Don't expect your boss to bring it up.

You Were Unfairly Penalized for Being a Woman

Unfortunately, even in 2013, this happens: In a study by Harvard researcher Hannah Riley Bowles, participants were shown videos of men and women asking for raises—using the same script. The results: Participants agreed to give the male participants raises, while the women were considered too aggressive and their requests too demanding.

While sexist and unfair, it may still be a reality female employees need to work around. In another experiment, two techniques helped to eliminate the different perceptions of women and men. First, says Riley Bowles, a woman should focus on how her performance has helped the company, and solicit feedback, with a simple: "What do you think?" It can also be effective to bring a third party into the conversation. For example: "My leader advised me to do this."

LearnVest's mission is to empower people everywhere to take control of their personal finances so that they can afford their dreams. They believe that financial planning should not be a luxury, which is why they've developed an advice-driven program that is personalized to your specific financial goals and situation.